Tungsten wires as a material of electric light source play an important role in the lighting industry. The major application of tungsten wire in electric light source is lighting. Besides, the tungsten wires as light emitting body in bulbs need to add potassium oxide, silicon oxide and aluminum oxides during production processes, so tungsten wire also is known as doped tungsten wire or Not-sag tungsten wire. With the development of economy and production technology of tungsten wire, tungsten wire can be applied to ordinary light bulbs, but also can be applied to a variety of high-performance bulbs. For example, doped a certain amount of K, Al, Si and other elements into tungsten powder to produce doped tungsten wire can not only improve the color temperature of filament, the light-emitting efficiency and service life, but also the tungsten wire has good high temperature anti-sag properties therefore it can be used as a halogen lamp and other special high-temperature filament. On the other hand, added some alloy elements such as Co into doped tungsten powder can be made of high-strength shock tungsten wire for vibration environment lighting application, such as motorcycles, cars, trains, airplanes’ lighting and so on. Besides, it also can apply to military use special light bulbs and heating wire of aerospace engine heating wire.

Tungsten wires not only are widely used in the field of electric light sources also developed in other areas. Added some alloy elements into tungsten powder or doped tungsten powder such as thorium, rhenium, cerium, yttrium, lanthanum or zirconium and other elements can be made of tungsten alloy wire. Tungsten alloy wire can be used as arc welding electrodes, thermocouple, CRT cathode filament, and filament electron emission tubes, and be used in various fields.

In addition, a small amount of tungsten wire is also used as a high-temperature furnace heating material, the heater of electronic valve and strengthening rib of composites.

Tungsten wires at room temperature have good acid and alkali capacity, but are easily oxidized in moist air, so it can not be placed and stored in a humid environment for long time.

Tungsten carbide ball V-slot grinding process has many advantages, such as even the vertical axis of nylon and other polymer materials can fully absorb drive vibration damping, thereby eliminating the impact of the grinding process; there is also a spacer ring in the periphery, so as to ensure the ball does not collide with each other, making the whole more orderly movement; since only the lower disc exercise pressure on the disc relative movement does not occur, a static pressure, more stable, and more conducive to the pressure adaption; the grinding area is relatively closed so that it is beneficial for grinding fluid mixing fully, which tungsten carbide balls are covered by grinding compound completely throughout the rotation and remarkably increasing the efficiency of grinding; the rotating speed is adjustable, the grinding compound can realize spontaneous circulation and the structure of grinding tray is simple to be replaced. It also can be manufactured according to different specifications, which greatly shorten grinding time and improve the precision of tungsten carbide ball.

In addition, tungsten carbide ball and the grinding disc have heightened modulus of elasticity and rigidity is good, can be considered ideal for the rigid contacts between the two, and has no deformation. Tungsten carbide ball isolation ring did not space, nor can contact between the interactions between the spheres also be negligible. In order to facilitate analysis of the physical movement of the ball along the direction of the contact surface made of pure rolling motion that the ball is in line with the abrasive disk at equal speed of the contact. Establish the A, B, C three contact points based on the mathematical model equations to calculate the spin angle θ, and the value of the spin angle θ depends on the diameter of the ball blank and the grinding disc guide groove, regardless of the grinding disc speed, general only in the case of near 0° values were basically does not change during processing. However, during processing of the workpiece and the grinding disc slide will change the value of θ, this change is a disorderly and uncontrollable factor.

There are many influencing factors of the grinding precision and efficiency of tungsten carbide ball, such as the material of tray, grinding slot, grinding fluid, the conditions and other grinding parameters, and the shape of grinding slot of the grinding tray is the most significant factor of the effect on the precision and efficiency of tungsten carbide ball. First of all, V-slot combined with carbide ball brittle, intolerance bump features and designed its angle according to the diameter of the sphere can make adjustments to the common angle is generally 45 °, 60 °, 90 °,120°.

Then placed on concentric groove ball blank disc between the two, so that in the state's three-point contact, under pressure, viscous force by rotating grinding disc friction and grinding fluid movement along the groove plate. The rotating tray, tungsten carbide ball, the fixed tray and grinding compound have interaction, which forms high pair (deputy campaign by two members point or line contact constituted collectively referred to as high pair.) between ball and the surface of tray groove. Finally, the blank balls extruded and wore to remove the finish allowance of the surface and ball milled gradually. The schematic of V-slot grinding tray and the movement principle diagram of V-slot grinding are given as follow:

The principle of the photoelectric conversion process is that the photon energy of the electrons and the subsequent transfer to form the current movement. There are two ways to resolve this process, the most common is to use solid means of silicon as the main material, and the other is to use photosensitive dye molecules to capture the energy of the photon. It will allow the dye molecules to absorb photon energy of the semiconductor in the negatively charging electrons and positively charging holes.

Tungsten trioxide (semiconductor material) is a photoelectric conversion process for the light incident on the semiconductor material, valence electrons will absorb the energy of the photon belt, and only when the photon energy is absorbed by electrons in the valence band, and it is large enough to meet the electronic transition to the conduction band. Photo-generated electron - hole after separation, is a hole in the surface of the oxide material of the photoelectric conversion sites. However, electronic transitions migrates to restore point will re-migrate to the outer circuit after the formation of the current conduction band or restoring point to achieve the photolysis of water to produce hydrogen.

Photoelectric conversion process of tungsten trioxide material is divided into three parts: the electronic absorption of light energy, light energy conversion an electron, transition occurs and the whole separation and electron transport to the outer circuit. After analyzing the main factors that affect the performance of the tungsten trioxide photoelectric conversion are: process photoanode prepared; crystalline nanostructure dimensions and materials; morphology nanostructure films; photoelectron and recombination and separation; and three photoelectron transmission tungsten oxide and other surface defects.

Microemulsion method refers to the two immiscible solvent to form an emulsion under the action of surfactant, heating treatment nano particles in microvesicles by nucleation, coalescence, agglomeration. Monodisperse particles are characterized by good interface. Monodisperse microemulsion system is thermodynamically stable, transparent water droplets in oil (w / o) or oil in water (O / W) is formed, its micro-particle structure is 5 ~ 70 nm, it is an ordered combination of surfactant molecules in the water. Schulman dropped alcohol in the emulsion in 1943，which is the first time to prepare transparent or translucent, and even long-term stable microemulsion.

The following steps to describe the preparation of tungsten trioxide:
1. Stirring 8ml of cyclohexane and 12ml of n-butanol.
2. The obtained mixed solution is divided into 2 parts of solution A and solution B, solution A is added in 6ml1: 1 hydrochloric acid solution, having 15min phacoemulsification.
3. The B solution is added 3ml sodium tungstate solution, having 15min phacoemulsification.
4. The emulsion is added dropwise to hydrochloric acid sodium tungstate solution until yellow solution is far from exacerbating.
5. Stop stirring, aging 16h, the supernatant liquid is removed, drying over anhydrous ethanol and washing several times with distilled water each, then centrifuged, and then put into the oven at 100 ℃ drying to obtain precursor.

With the decreasing of high-quality tungsten ore, tungsten ore with high molybdenum has increasingly become an important raw material in metallurgy of tungsten, and it requires higher technology in separation of tungsten and molybdenum. A new ion exchange method based on three column series which is used to removing molybdenum in tungsten ore or fine mud to get pure ammonium paratungstate in low cost is presented in this paper. Three column ion exchange adsorption has a high capacity in adsorption and removing molybdenum effectively (the rate beyond 95%), reduce the number of resin regeneration and tungsten loss, also the consumption of auxiliary materials has been cut down.



Steps are as follows:
1. Ball grounding tungsten ore or fine slime, leaching with alkali, filtering, and concentrated to obtain sodium tungstate crystal;
2. Dissolve in and filter the sodium tungstate, then vulcanization;
Control WO₃ in sodium tungstate solution at 130-180g/L, pH value less than 12, adding Na₂S solution in accordance with S₂^- 1 ~ 8g/L, and then with adjust pH value to 7~10 by dilute H₂SO₄, heating to 60-80℃ and insulation for 0.5 to 5 hours;
3. Remove molybdenum by ion exchange;
4. Remove sulfur from sodium tungstate;
Inlet air into sodium tungstate under the condition of alkaline, and heating to make S₂^- to turn into sulfur or sulfide precipitation;
5. Remove impurities by method of ion exchange, then desorbs tungsten with ammonia and ammonium chloride solution to prepare ammonium tungstate;
6. Evaporate and crystallize to get APT.

Technology of ion exchange has brought significant technical progress in China's tungsten smelting, but it also has some defects at the same time. Especially wastewater generated from ion exchange has gradually become prominent with the environmental issues becoming more important. It mainly comes out in the following aspects:
1. Low feed concentration, and the large water consumption standout;
2. The low unit handling capacity of strong basic resin makes the small work of exchange capacity;
3. Wastewater is in large amount and difficult to deal with.

Ion exchange method base on Weak-base anion-exchange resin to prepare ammonium paratungstate is proposed in this paper. Specific steps as follows:
1. Tungsten concentrate was treated with alkali and alkaline sodium tungstate obtained;
2. Add acidic substances into the alkaline solution and heat for neutralization to get neutral sodium;
3. Dilute sodium tungstate to get pre-exchange solution;
4. Use Weak-base anion-exchange resin to adsorb tungsten;
5. Use of desorbent for desorbing Weak-base anion-exchange resin with tungsten, and get desorption;
6. Removing impurities in the desorption;
7. Evaporate and crystallize the solution to obtain ammonium paratungstate.

Using ion exchange method based on Weak-base anion-exchange resin for preparing ammonium paratungstate, can shorten the process, complete the tasks of removing impurities and transformation at the same time. Besides it got high recovery rate of tungsten with sample equipment, and effectively improves the concentration of tungsten in the feed solution of ion exchange process. Also it cuts down the amount of wastewater, and prepare qualified APT products ultimately.

Both direct current (DC) plasma spraying and radio frequency induction plasma spraying were conducted in the spraying chamber connected to a vacuum system. The soft vacuum/low pressure (10-30KPa) of the spray chamber was used for preventing the oxidation of tungsten particles melted in plasma. Ar was used as secondary plasma gas. The substrate used is a hollow copper cylinder with approximately 20mm in diameter and 400mm in length. The hollow cylinder was mounted on a rotary shaft cooled by high pressure cooling water. Fine tungsten powder used as spray feedstock has the mean particle size of 5μm and coarse tungsten powder has the particle size in the range from 45μm to 75μm.

During DC plasma spraying, tungsten coatings were generated by moving plasma horizontally on the rotary copper substrate. A sphere-shaped chamber with about 1500nm in diameter was used. Tungsten powder was laterally fed into the plasma via two opposite powder injectors. In addition, during radio frequency induction plasma spraying, tungsten coatings were generated by moving the copper substrate horizontally and rotating it simultaneously because plasma torch was fixed to an oscillating unit of power supply system and could not be moved. On the contrary, lateral injection of powders in DC plasma spraying, tungsten powders were axially fed into the center of the plasma with a water-cooled powder injector in induction plasma spraying. It should be pointed out that spray distance was calculated from the tip of water-cooled powder injector to the surface of the copper substrate. Tungsten coatings on the substrate were cooled to room temperature before being taken out from the spray chambers. Coating samples were cut by a low speed rotary diamond saw. After being ground and polished, the samples were examined under scanning electron microscope (SEM). Density of the coating, chiseled from the copper substrate, was measured using the method of water displacement.